Rotary shaft sealing is classified as dynamic sealing. Since there is relative movement between a rotating shaft surface and its surrounding wall, a clearance gap exists and fluid will eventually leak through this gap no matter how small it is. There are some practical sealing methods for rotary shafts: labyrinths, stuffing boxes, lip seals, bushings, and spiral-groove seals. Also, mechanical seals made out of a very large number of materials are commonly used for sealing rotating shafts. However, all of the above are not hermetic sealing methods. They can only reduce or delay the leakage of fluid. This can not be tolerated for industrial areas that handle toxic and radioactive fluid, for example. The leakage of fluid through the rotary shaft also becomes a main problem in many industrial machine designs.
Other solutions of rotary shaft hermetic sealing are found in “Fluid Sealing Technology-Principles and Applications”, by Heinz K. Muller and Bernard S. Nau. In the Muller book, the first example provided is hermetic sealing through a nonmagnetic diaphragm and magnetic transmission of motion. Another example uses metal bellows that envelop a crank in which its axis follows a conical orbit during rotation. The movement can then be transferred through an angled bore in the end of the output shaft.
Both solutions mentioned above have critical disadvantages: using magnetic force does not fully transfer the torque since the drive shaft and the load shaft are not physically connected. Also, the output rotation has phase lag with respect to the input rotation, making it uncontrollable. The second solution, on the other hand, has a physical connection between the input shaft and the output shaft though an angled bore, but its structure is not capable of high rpm's. The configuration of this structure easily deforms if large amounts of torque and load are applied.
It is therefore an object of the invention to function as a hermetic sealing for rotary shafts.
It is another object of the invention to fully transfer the drive torque in the same way as a continuous solid shaft.
It is another object of the invention to monitor defective rubber seal failure and control rotary shaft operation.
It is another object of the invention to work in both static and dynamic environments.
It is another object of the invention to work under various rpm's.
It is another object of the invention to work under various loads.
It is another object of the invention to work longer without replacements of sealing parts.
It is another object of the invention to work under a pressurized environment.
It is another object of the invention to simplify the rotary shaft without a highly expensive surface finishing.
It is another object of the invention to be environmentally friendly.
It is another object of the invention to be economically efficient.